This invention relates to a closed system chemical handling and delivery system and method. More particularly, this invention relates to devices and methods for handling, mixing, diluting, and/or delivering chemicals under vacuum into a streamline.
The use and handling of various chemicals, such as agricultural chemicals, are subject to a range of regulations and best practices. Direct or prolonged exposure to certain chemicals may have adverse effects on the handlers of these chemicals, such that excessive exposure is typically minimized. In addition, contamination of the surrounding environment with these chemicals is preferably minimized or eliminated.
One particular issue arises when these chemicals are being prepared for introduction into a streamline for downstream application. “Closed systems” for chemical mixing and diluting have been proposed to minimize a handler's exposure to the chemicals being handled, and any ensuing undesirable environmental contamination. For example, one type of “closed system” is commonly referred to as a Goodwin-type box. Goodwin-type boxes provide a sealed-off environment, typically in the form of a metal enclosure, allowing a handler to place entire containers of chemicals inside the enclosure before sealing off the enclosure. The handler can then actuate a handle or lever that causes a series of knives/blades to move within the enclosure puncturing the containers, thus allowing the chemicals to mix within the enclosure. This approach disadvantageously requires use of an entire chemical container as there is no reasonably practical way to reseal a punctured chemical container. In addition, once a chemical container is sealed within a Goodwin-type box, there is no access to the container to meter a desired amount of chemicals, resulting in chemical waste or required pre-mixing measurements that have the potential to undesirably expose the handler and the ambient environment to the various chemicals.
Other types of mixing systems require a handler to place adapters and hoses directly onto the chemical containers and then mix the chemicals together. This type of “open” mixing increases the possibility of both handler and environmental exposure to the chemicals. Moreover, dry or powder chemicals are not amicable to this type of mixing.
There is a need for a closed system chemical handling and delivery system and method that allows for handling, mixing, diluting, and/or delivery of a measured amount of chemicals, in a sealed environment, while also having the flexibility to accommodate liquid and powder chemicals for delivery under vacuum into a streamline.